The adsorption of PCB's into river clay depends on the size of the clay particle, the type of particles (elemental analysis) and the geometry of the clay particles. High voltage electron microscopy was used to determine the clay particle size, elemental composition and shape. We hope to be able to locate the actual adsorption sites in the future. This work was conducted as part of a Ms. Zaidi's PhD thesis in the SUNY-Albany, School of Public Health.